This invention relates generally to turbomachinery compressors and more particularly relates to dirt extraction in such compressors.
A gas turbine engine includes, in serial flow communication, a compressor, a combustor, and turbine. The turbine is mechanically coupled to the compressor and the three components define a turbomachinery core. The core is operable in a known manner to generate a flow of hot, pressurized combustion gases to operate the engine as well as perform useful work such as providing propulsive thrust or mechanical work.
It is a recognized problem that the presence of dirt in the gas path and turbine cooling air flow of a gas turbine engine results in reduced durability and increased performance deterioration. Also, thermal barrier coatings (“TBC”) found in gas turbine engines are susceptible to attack by calcium-magnesium alumino-silicate (“CMAS”) melts produced when silica-based debris is ingested.
Deflectors have been used in the turbine systems of such engines, with limited success. Inlet particle separators have also been used and are effective on larger particles, but relatively ineffective for smaller sizes that tend to cause the majority of turbine issues.
Accordingly, there remains a need for a means for removing dirt from the flowpath of a gas turbine engine.